* Convert zstd feature to default disable
* All autoconf test use one standard template
To simplify the testing, cross-compilation and repeatable build process,
no configure options are automatically probed for - they all default to
off and are all using the same template.
The --with-x options should be deprecated and replaced with --enable-x
because there is no syntax checking for --with options in autoconf.
There are still some differences between the config options, but this
should provide a starting point.
* Remove unused code from the autoconf
* Remove warnings from default build
* Avoid calling port mapping functions if none are enabled
* Start with all builds in neutral config
* Add more missing code guards
* Adjust code guard location to placate cmake
Hamish Coleman
4f568b03c1